The intricate geometry inside this Baroque-style dome was designed to create "terror of the human soul."

BDSM, 1930s Style.

This surreal statue brings a famous French novel about a supernatural cad to arresting life.

Paris' fabled purveyor of exotic taxidermy and natural history curios.

Original cabaret handbills, posters, and feline artwork are a purrfect highlight of the Museum of Montmartre.

France's national museum of scientific and industrial instruments.

A counter-culture bookstore like no other hides in plain sight in the streets of Paris.

The most peculiar part of Berlin's public transit network is an on-demand rowboat.

After local authorities changed the design, the building's architect, Le Corbusier, wanted nothing to do with it.

This public observatory is home to the "celestial cannon," the longest pointable telescope in the world.

You've probably seen these distinctive orange-tiled columns on the big screen.

Superb sweets await at the first Jewish bakery inducted into Berlin’s prestigious baker’s guild.

For more than 170 years, this family-run bakery has been serving Berlin’s best Baumkuchen, or “tree cake.”

Floating swimming pool within a moored vessel.

A unique Holocaust memorial tells the personal stories of the Jewish residents exiled from greater Berlin.

A tree-like building perches on its trunk in the Steglitz neighborhood of Berlin.

A square-domed symbol of resilience in the heart of the old Jewish Ghetto.

When this 400-year-old fountain fell into disrepair, officials covered the mess up with what looks like a giant soup tureen.

This small church was constructed over the ruins of three temples dating to the Roman Republic.

Italian horror legend Dario Argento’s own shop hides a sinister museum-dungeon in the basement.

Remnants of a 4th-century church with vivid medieval frescoes and ancient sarcophagi hide beneath this old basilica.

This curious, round temple is the oldest still-standing marble building in Rome.

A neo-Gothic church built to thank God for saving the Emperor of Austria from an assassination.